A new study published in the Journal of Neuroscience suggests how having a viral infection during pregnancy might increase the risk of having a child with autism or schizophrenia.
Previous research has suggested autism may be caused by changes in the development of connections in the brain.
This new study found that activating a mother’s immune system during her pregnancy can lead to disruption in the development of neural cells in the brain of her offspring, damaging the cells’ ability to send signals to each other.
“This is the first evidence that neurons in the developing brain of newborn offspring are altered by maternal immune activation,” Kimberley McAllister, the study’s senior author explained. “Until now, very little has been known about how maternal immune activation leads to autism spectrum disorder.”
The study used mice and rats as the subjects, and activated the immune systems of some rodents while they were pregnant. Then they compared the brains of the offspring. The newborns that were exposed to viral infection were found to have higher brain levels of immune molecules called MHCI molecules.
This is evidence that maternal immune activation alters MHCI levels on the surface of offspring’s neurons. High MHCI levels impair the neurons in the newborn’s brains to form synapses (responsible for transmitting signals across brain cells). When researchers reduced high MHCI to normal levels, the typical amount of synapses was formed.
“These results indicate that maternal immune activation does indeed alter connectivity during prenatal development,” McAllister said.
The results of this study may help scientists develop diagnostic tests and eventually even therapies to improve the lives of those with autism and other neurodevelopmental disorders.